USB Aircraft MP3 Player II is not only a portable stereo speaker, but also a MP3 player. Built-in a USB port and SD(HC) memory card Slot which can read SD(HC) memory card and USB flash memory for playing MP3/WMA audio files directly. It also allows to connect to all iPods, MP3, MP4, MD, CD player, notebook, PC, PDA, PSP, mobile phone and other digital products with 3.5mm stereo audio connector. Built in Lithium Ion battery - convenient to use.